National Repository of Grey Literature 71 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Water Jet 2017 - Research, Development, Applications. Proceedings of the Conference on Water Jetting Technology
Klichová, Dagmar ; Sitek, Libor
Conference Water Jet 2017 – Research, Development, Applications coincides\nwith major changes in key technologies and economy which recently started to\nincrease pace.\nUpcoming electric mobility will strongly influence production technology in\nthe automotive industry leading probably to declining content of water jetting\nprocesses.\nThe continuing trend for automation will have an extreme impact on water jet\nbusiness. Merging robotic and data control systems with smart water jet tools will\nbe a demanding future task.\nThe need for energy saving remains unchanged and directs scientific focus on\nhigh efficient jetting, cutting and cleaning processes as well as tools. This is\nthe only way to gain substantial savings as efficiency of state of the art pump\nsystems is already on a very high level.\nTraditional technologies are moving towards marine applications. Subsea\nexploration becomes more and more important for basic raw material supply. Both\nmaintenance and decommissioning of vessels and offshore structures is already\na growing domain for special water jetting applications. Aquafarming substantially\ncontributes to supply a constantly growing human population with sea food\nwhereat water jet cleaning helps to keep high quality farming standards.\nAll these changes are linked up with associated HSE requirements. High\nefficiency, safe, ergonomic and reliable equipment as well as water treatment are\nkey factors for future developments.\nA strong scientific and engineering effort is required to meet these current and\nfollowing challenges. Water Jet 2017 Conference is organized by the Department of\nMaterial Disintegration of the Institute of Geonics.
Erosion capability of ultra-high-speed continuous waterjet and pulsating waterjet: the comparison
Sitek, Libor ; Hlaváček, Petr ; Klichová, Dagmar ; Trieb, F. ; Pude, F.
Advantages and possibilities of continuous ultra-high-speed waterjets (with\npressures of 600 MPa and more) when cutting metals are well known to\nthe professional public both from scientific studies and from practice. In addition\nto efficiency increased as water pressure increases and reduced water\nconsumption, abrasive consumption can also be reduced in the case of abrasive\nwaterjet. Ultra-high-speed waterjet technology allows not only to cut metal sheets\nwith pure water, but also allows cutting of harder materials such as ceramics.\nDespite the initial suspicion and technical problems associated with the reliability\nand sealing of some hyperpressure elements, high-pressure devices generating\nwater pressures around 600 MPa are now commercially available. However, no\ncomparison has been made so far concerning the efficiency of these jets with\nacoustically modulated high-speed pulsating waterjets using relatively low\npressures and higher water flow rates when eroding metallic materials.\nThe article compares cuts made by pure ultra-high-speed waterjet generated at\nhyperpressures (from 500 to 800 MPa) with erosive capabilities of pulsating\nwaterjets generated on the contrary at water pressures in the order of tens of MPa\non three metallic materials (stainless steel, mild steel and copper) using the same\njet hydraulic power.
Properties and characteristics of recycled garnet abrasives for AWJ
Martinec, Petr ; Hlaváček, Petr ; Ruppenthalová, Lucie ; Sitek, Libor
The use of recycled garnet abrasive from sludge after cutting materials is a current\nproblem. The behavior of individual garnet abrasives in the AWJ process depends\non the geological origin of the garnets, which also affects all the material\ncharacteristics of the garnet recyclate. The parameters of the BARTON HPX80 and\nGMA 80 abrasive inputs and their recycled products were compared: mineralogical\ntype, apparent density, granularity, grain shape and mineralogical purity,\nmicrohardness data and the degree of damage to the garnet grains. All individual\nparameters of abrasives and their recyclates are reflected in the index of cutting\nefficiency of abrasive. The effect of abrasive material properties on cuttability of\nabrasives is synergistic. The new parameters in the evaluation of abrasives are\nmicro-hardness (brittleness criterion), specific surface and pore size distribution\n(internal grain damage criterion).
Abrasive water jet drilling of cooling holes in aeroengines: preliminary experimental study
Hlaváček, Petr ; Zlámal, T. ; Sitek, Libor ; Georgiovská, Lucie
This paper addresses an experimental investigation on the feasibility of using\nabrasive water jet (AWJ) for the drilling of small-diameter holes in aeroengines\ncomponents. These components are sprayed with ceramic thermal barrier coating\n(TBC). The required holes are typically 0.5 to 1 mm in diameter with a drilling\nangle of 30 to 90 deg. The parameters of the AWJ were varied to study their effects\non both quantitative and qualitative hole drilling parameters.
Application of high speed water jet technology for concrete repair
Bodnárová, L. ; Sitek, Libor ; Foldyna, Josef ; Jarolím, T.
This article brings selected knowledge from the long-term cooperation between\nthe Brno University of Technology, the Faculty of Civil Engineering, the Institute of\nTechnology of Building Materials and Components, and the Academy of Sciences of\nthe Czech Republic, v.v.i., Institute of Geonics, Ostrava – Poruba in the field of\nthe interaction of high-speed water jets and concrete, especially with regard to\nthe use of high-speed water jet technology for the removal of surface layers of\nconcrete during repair of concrete.
Use of micro X-ray computed tomography for development and research into waterjets
Souček, Kamil ; Sitek, Libor ; Gurková, Lucie ; Georgiovská, Lucie
Non-destructive methods for analysis of various types of materials have been increasingly applied recently. One of these methods is the industrial micro X-ray computed tomography (CT). This paper presents an overview of experience in using the industrial micro X-ray computed tomography during research activities at the Institute of Geonics of the CAS. It discusses possibilities of the nondestructive visualization of the inner structures of a wide range of materials and objects, including examples of its use in research and development activities related to high speed waterjets.
Abrasives and possibilities of increase in efficiency of abrasive waterjets
Martinec, Petr ; Sitek, Libor
The contribution focuses on the research into abrasive materials and possibilities of adjustment of their properties in order to increase the efficiency of the processes of machining and cutting with abrasive waterjets. Cutting ability of commonly available garnet concentrates and nontraditional products which are starting to access to the Czech market were tested and compared. In addition, entirely new garnet products which are not commercially available yet, recycled abrasives, abrasives with various sizes of grains and heat-affected abrasives or abrasives coated with a thin plastic layer were studied.
Water jet 2015 - Research, Develompent, Applications
Sitek, Libor ; Klichová, Dagmar
The fourth international meeting of producers, users, designers and other public interested in the technology of high speed water jet. Forum for the exchange of knowledge, information and experiences in areas of research, development and application of the water jet (cutting, machining, repair of structures, cleaning, removal of coatings and layers, hydrodemolition, mining, abrasive materials, special applications of the water jet, high-pressure technique, safety aspects, etc.).
Preliminary study using pulsating water jet for bone cement demolition
Hloch, Sergej ; Kloc, J. ; Foldyna, Josef ; Pude, F. ; Smolko, I. ; Zeleňák, Michal ; Sitek, Libor ; Hvizdoš, P. ; Monka, P. ; Monková, K. ; Kozak, D. ; Stoić, A. ; Sedmak, A. ; Milosevic, M. ; Lehocká, D. ; Mihalčinová, E.
The paper deals with the study of using the selective property of ultrasonic pulsating water jet for the disintegration of bone cement which creates the interface between femoral stem and trabecular bone tissue. For investigation, commercial bone cements were used. Bone cements were tested by nanoindentation in order to review their mechanical properties. A representative sample Palacos R+G was selected for disintegration of bone cement. Bone cements samples fixed between two plexiglasses were disintegrated using ultrasonic water jet and water jet generated by self-resonating nozzle at the pressure level of 20 MPa. Visualisation of bone cement demolition was provided with high speed 1 kHz cameras with two led pulsed sources. Potential were observed for using of pulsating water jet for bone cement demoliton during femoral stem extraction.
Concrete damaged by high temperature – possibilities of treatment with high speed water jet
Bodnárová, L. ; Válek, J. ; Sitek, Libor ; Foldyna, Josef ; Klich, Jiří
The paper describes analysis of behavior of cement based composite materials (concrete) exposed to high temperature. Recommendations for minimization of damage of thermally loaded structures are proposed and possibilities of renovation of fire damaged concrete using the technology of high speed water jet to remove damaged layers are given.

National Repository of Grey Literature : 71 records found   1 - 10nextend  jump to record:
Interested in being notified about new results for this query?
Subscribe to the RSS feed.